To qualify for renewal of a certificate under this subtitle, a certificate holder shall earn during each 2-year certificate term at least one continuing education unit in two or more courses that the Board approves. A continuing education unit consists of 10 hours of study. A certificate holder who is granted a certificate during the second year of a certificate term may renew the certificate for the next full term if the certificate holder earns at least one-half of a continuing education unit in one or more courses that the Board approves.